Resilient poppet valve

ABSTRACT

A lightweight poppet valve having a resilient poppet in which the radius of the spherical contact surface is slightly larger than the radius of the spherical contact surface of the metal valve seat such that as the pressure behind the poppet increases the poppet gradually assumes the shape of the valve seat to form a tight seal.

United States Patent Schneider [45] May 23, 197 2 [54] RESILIENT POPPETVALVE 3,113,587 12/1963 l-lendley v.137/5195 2,676,782 4/1954 Bostock etal. ..l37/543.l9 X [72] Invent Schneider Annamhs 3,101,739 8/1963Pribonic ..137 539.5 x [73] Assignee: The United States of America as3,465,786 9/ 1969 Spisak 137/5 l6.27 repr n y h Secretary of h N y3,536,094 10/1970 Manley ..251/333 X [22] Filed: Oct. 23, 1970 PrimaryExammerRobert G. NllSOl'l [2!] App 83,571 Assistant Examiner-David J.Zobkiw Attorney-R. S. Sciascia and Q. E. Hodges [52] US. Cl..l37/516.29, 137/525, l37/543.l9 51 1m. 01 ..Fl6k 15/00 1 ABSTRACT [58]Field ofSeai-ch ..137/5l6.25,516.27,5l6.29, A H I 4 ghtwe1ght poppetvalve having a res1l1ent poppet in which 137/5195 54119 the radius ofthe spherical contact surface is slightly larger 251/332 334 than theradius of the spherical contact surface of the metal valve seat suchthat as the pressure behind the poppet in- [56] Reierences cued creasesthe poppet gradually assumes the shape of the valve UNITED STATESPATENTS Seat to form a tight seal 3,457,949 7/ 1969 Coulter 1 37/516.27X 3 Claims, 3 Drawing Figures PATENTEDmza I972 3, 664, 37 l FIG. 2.

FIG. 3.

IN VEN TOR. WILL MM E. SCHNEIDER A r Tom E Y RESILlENT POPPET VALVE Theinvention described herein may be manufactured and used by or for theGovernment of the United States of America for Governmental purposeswithout the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION Prior to the use of a lightweight resilient,plastic poppet, metal poppets were used in this type of valve. The speedat which the valve could open and close is a function of the weight ofthe moving poppet. If the valve is to operate efficiently, the movablepoppet must require as small a force as possible to cause it to move.Also, if the valve is to open (the poppet move off its seat) at lowinlet pressures the valve spring must only exert a small force upon thepoppet. Thus the fluid force which causes the valve to open and thespring force which causes it to close again will be small. Stainlesssteel has previously been used as the poppet material. It isapproximately four times heavier than the plastic poppet. Its inertiaforces are then four times as great. The inertia force is the forcerequired to speed up or slow down an object of a given weight. Thepoppet must be accelerated from its closed position to its open positionby the force of the incoming water and accelerated from its openposition to its closed position by the valve spring. A plastic poppetcould do this four times faster than the much heavier stainless steelpoppet with the same amount offorce applied.

When a spherical shaped metal poppet is in contact with its metal valveseat, water could leak through at the point of contact. An o-ring sealwas required to make a leak tight seal. If pressure is increased on theoutlet side of the valve the rubber O-ring is forced into any spacewhich may exist between the poppet and the valve seal. If the metalpoppet and metal valve seat do not match each other exactly, there willbe unfavorable stress distribution in the poppet. The same situationwill arise if sand, dirt, or any other hard particles get caught betweenthe poppet and the valve seat. This type of interference between thepoppet and the valve seat may be serious enough to prevent propersealing and cause the valve to leak. These hard particles will alsocause dents and other deformations in both the poppet and valve seat andmay in time prevent proper operation of the valve.

SUMMARY OF THE INVENTION The general purpose of this invention is toprovide a valve which can be used in high speed, high pressure, seawaterpumps. It is capable of operating at up to 60 cps and against a pressureof 10,000 psi with minimum leakage. In addition, the valve is highlyresistant to the corrosive and abrasive fluids such as silt ladenseawater which may flow through it.

To attain this, the invention utilizes resilient plastic materials topermit more effective sealing and higher speeds of operation then wouldbe possible with similar parts made of metal. The resilient poppet movesin such a way as to cover and uncover flow passages in the valve body. Aspherical valve seat in the valve body is used to contain the movablepoppet when it is in its closed position. A rubber ring of roundcrosssection or O-ring is positioned in the valve in such a way as toact as an additional means of sealing when the poppet is firmly in itsseat. A poppet return spring of low force is used to hold the poppetagainst the seat until the fixed pressure is built up on the inlet sideof the valve to cause the poppet to move off its seat. This spring alsoreturns the poppet to the seat when the inlet pressure is removed. Avalve cap is used to position and contain the spring. It also provides alip which prevents the O-ring seal from being washed out of position aswater rushes through the valve.

OBJECT OF THE INVENTION The general purpose of this invention is toprovide a valve having a resilient plastic poppet requiring less forceto accelerate or for the same forces capable of operating at muchgreater speed than a poppet made of higher density material.

It is another object of the invention to provide a valve having a poppetmade of resilient material which will yield and assume the shape of therigid metal valve seat. The higher the pressure becomes the more thepoppet yields to fit the shape of the valve seat and the tighter it willseal.

Still another object of the instant invention is to provide a valve inwhich hard particles of sand, shell or any other contaminate will notcause denting or chiping in the valve seat.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view, completely insection, of the valve in the open position.

FIG. 2 is a section view showing the resilient poppet positioned incontact with the valve body.

FIG. 3 is a view of the resilient plastic poppet after high pressure hasbeen applied to the poppet to seat the poppet.

DESCRIPTION OF THE PREFERRED EMBODIMENT With continued reference to thedrawing, FIG. 1 shows, completely in section, the complete valvestructure. A resilient plastic poppet l is moved to cover or uncover aflow passage 2 in the valve body 3. When the poppet is not in contactwith the valve seat the valve is opened and fluid can flow through theinlet side I of the valve through to the outlet side 0. When the poppetis in contact with the valve seat fluid is prevented from returning intothe inlet side of the valve.

The radius of the spherical contact surface from the poppet 1 isslightly larger than the radius of the spherical contact surface of thevalve seat 4.

FIG. 2 shows that when the poppet is brought into contact with the valveseat there would only be a very small ring of contact at the outer edgeof the valve seat 4. If a pressure were built up on the outlet side 0 ofthe valve it would-tend to force the resilient poppet into the rigidmetal valve seat 4. At some pressure, depending upon the resiliency ofthe plastic used and the difference in the spherical radii of the poppetand valve seat, the poppet would assume the shape of the seat and form atight seal as shown in FIG. 3. It is considered merely a design detailthat the poppet has sufficient rigidity to seal without being forcedthrough the opening.

This valve also utilizes a rubber O-ring seal 5 as shown in FIG. 1 toprovide for more complete sealing at pressures to low to deform thepoppet into the shape of the valve seat. The O-ring is positioned suchthat the fluid pressure will tend to force it into any 'voids created bya mismatch of the poppet and valve seat. A retaining lip 8 is providedto maintain the O- ring seal in its proper position. The lip may beincorporated into the valve cap 7 which is also used to position thepoppet return spring 6. This spring is used to return the poppet tocontact the valve seat after the fluid pressure tending to open thevalve has been removed.

Even if the valve unit should be subjected to high temperatures whichmight cause deformation in the resilient poppet, upon application ofpressure thereto as above described, the resilient poppet and the valveseat will be pressed rightly together for effective sealing action andthe greater the pressure the more dependable the seal.

Since the resilient poppet is deformable to provide a dependable seal asabove noted, extremely close tolerance in the manufacture of the poppetand the valve seat is not required, thereby reducing the cost of theunit. Also, slight wear due to fluid flow will be compensated by reasonof the deflection of the resilient poppet.

It is understood that the invention is not limited to the exact detailsof construction shown and described, for obvious modifications willoccur to persons skilled in the art. It is therefore to be understoodthat within the scope of the appended claims the invention may bepracticed otherwise than as specifically described.

What is claimed:

1. A poppet valve assembly comprising:

a valve seat having a flow passage therethrough, said valve seat havinga concave spherical contact surface; and

a resilient poppet adapted to adjustably seat against said valve seat toprevent fluid from flowing from said flow passage, said resilient poppethaving a convex spherical contact surface, the radius of said convexspherical consurface with further sealing contact of the resilientpoppet with the valve seat whereby the seating force on the poppet ismaximized.

2. The apparatus of claim 1 wherein said resilient poppet is tactsurface being greater than the radius of said concave 5 made completelyOfplasticspherical contact surface at initial contact of the resilientpoppet with the valve seat, and wherein subsequently the radius of saidconvex spherical contact surface becomes the same as the radius of saidconcave spherical contact 3. The apparatus of claim 1 wherein O-ringsare attached to said valve seat to contact said resilient poppet tosupplement fluid sealing.

1. A poppet valve assembly comprising: a valve seat having a flowpassage therethrough, said valve seat having a concave spherical contactsurface; and a resilient poppet adapted to adjustably seat against saidvalve seat to prevent fluid from flowing from said flow passage, saidresilient poppet having a convex spherical contact surface, the radiusof said convex spherical contact surface being greater than the radiusof said concave spherical contact surface at initial contact of theresilient poppet with the valve seat, and wherein subsequently theradius of said convex spherical contact surface becomes the same as theradius of said concave spherical contact surface with further sealingcontact of the resilient poppet with the valve seat whereby the seatingforce on the poppet is maximized.
 2. The apparatus of claim 1 whereinsaid resilient poppet is made completely of plastic.
 3. The apparatus ofclaim 1 wherein O-rings are attached to said valve seat to contact saidresilient poppet to supplement fluid sealing.